Looking for BLE example for UNO R4 WFi

al1fch

Hi

I'm looking for a BLE exemple for an UNO R4 WiFi board (ArduinoBLE library used)
Best Regards,
Alain

kl3m3n

try the code below (install the latest ArduinoBLE library through Library Manager).

/*
 * GUI-O Basic BLE example for Arduino UNO R4 WiFi
 *
 * Uses the ArduinoBLE library and Nordic UART Service (NUS) UUIDs.
 *
 * Connect an LED (with a suitable series resistor) to PWM pin D9.
 * The onboard LED is not used because brightness control requires PWM.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <ArduinoBLE.h>

namespace led {
  constexpr uint8_t PIN = 9;  // UNO R4 WiFi PWM-capable pin
}

namespace uuid {
  constexpr char SERVICE[] = "6E400001-B5A3-F393-E0A9-E50E24DCCA9E";
  constexpr char RX[]      = "6E400002-B5A3-F393-E0A9-E50E24DCCA9E";
  constexpr char TX[]      = "6E400003-B5A3-F393-E0A9-E50E24DCCA9E";
}

namespace ble {
  // A 20-byte payload works without depending on a larger negotiated MTU.
  constexpr size_t NOTIFY_CHUNK_SIZE = 20;
  constexpr int RX_BUFFER_SIZE = 512;
}

void parseGuioMsg(const String &msg);
void sendMsg(const String &msg);

BLEService nusService(uuid::SERVICE);

// GUI-O writes commands to RX.
BLECharacteristic rxCharacteristic(
  uuid::RX,
  BLEWrite | BLEWriteWithoutResponse,
  ble::RX_BUFFER_SIZE
);

// UNO R4 sends GUI commands through TX notifications.
BLECharacteristic txCharacteristic(
  uuid::TX,
  BLENotify,
  ble::NOTIFY_CHUNK_SIZE
);

bool wasConnected = false;

void setup() {
  Serial.begin(115200);

  pinMode(led::PIN, OUTPUT);
  analogWrite(led::PIN, 0);

  if (!BLE.begin()) {
    Serial.println("Failed to initialize BLE!");
    while (true) {
      delay(1000);
    }
  }

  BLE.setLocalName("BasicBLE_NUS");
  BLE.setDeviceName("BasicBLE_NUS");
  BLE.setAdvertisedService(nusService);

  nusService.addCharacteristic(rxCharacteristic);
  nusService.addCharacteristic(txCharacteristic);
  BLE.addService(nusService);

  BLE.advertise();
  Serial.println("BLE advertising started.");
}

void loop() {
  BLE.poll();

  BLEDevice central = BLE.central();
  const bool connected = central && central.connected();

  if (connected && !wasConnected) {
    Serial.print("Connected to: ");
    Serial.println(central.address());
    wasConnected = true;
  }

  if (!connected && wasConnected) {
    Serial.println("Disconnected!");
    wasConnected = false;

    // Explicitly resume advertising for reliable reconnection.
    BLE.advertise();
  }

  if (connected && rxCharacteristic.written()) {
    const int length = rxCharacteristic.valueLength();

    if (length > 0) {
      String msg;
      msg.reserve(length);

      const uint8_t *value = rxCharacteristic.value();
      for (int i = 0; i < length; ++i) {
        msg += static_cast<char>(value[i]);
      }

      parseGuioMsg(msg);
    }
  }
}

/***************************/
/* IMPLEMENT YOUR GUI HERE */
/***************************/
void sendMsg(const String &msg) {
  if (!wasConnected) {
    return;
  }

  const uint8_t *data = reinterpret_cast<const uint8_t *>(msg.c_str());
  size_t remaining = msg.length();

  while (remaining > 0) {
    const size_t chunkLength =
      remaining > ble::NOTIFY_CHUNK_SIZE
        ? ble::NOTIFY_CHUNK_SIZE
        : remaining;

    if (!txCharacteristic.writeValue(data, chunkLength)) {
      Serial.println("Failed to send BLE notification.");
      return;
    }

    data += chunkLength;
    remaining -= chunkLength;

    BLE.poll();
    delay(10);
  }
}

void parseGuioMsg(const String &msg) {
  if (msg.startsWith("@init")) {
    Serial.println("GUI-O app is requesting INITIALIZATION!");

    // Clear screen and set background.
    sendMsg("@cls\r\n");
    sendMsg("@guis BGC:#FFFFFF\r\n");
    delay(100);

    // Initialize simple example GUI.
    sendMsg("|LB UID:title X:50 Y:15 TXT:\"Simple light switch\" FFA:\"font8\" FSZ:3.5\r\n");
    sendMsg("|LB UID:tap_me X:50 Y:70 TXT:\"TAP ME!\" FFA:\"font8\" FSZ:3 FFA:\"font5\"\r\n");
    sendMsg("|CB UID:brightness X:50 Y:50 W:90 BTH:5 HAH:8 HAW:8 VIS:0 STA:135 ENA:45 FGC:#000000 SFGC:#FFFF00 BGC:#CBCBCB\r\n");
    sendMsg("|IM UID:light_off X:50 Y:50 IP:\"https://i.imgur.com/3VbsS0Z.png\" VIS:1\r\n");
    sendMsg("|IM UID:light_on X:50 Y:50 IP:\"https://i.imgur.com/gNdck9A.png\" VIS:0\r\n");
  }
  else if (msg.startsWith("@light_off")) {
    Serial.println("GUI-O app is requesting LIGHT ON!");

    sendMsg("@light_off VIS:0\r\n");
    sendMsg("@light_on VIS:1\r\n");
    sendMsg("@brightness VIS:1 VAL:100\r\n");

    analogWrite(led::PIN, 255);
  }
  else if (msg.startsWith("@light_on")) {
    Serial.println("GUI-O app is requesting LIGHT OFF!");

    sendMsg("@light_off VIS:1\r\n");
    sendMsg("@light_on VIS:0\r\n");
    sendMsg("@brightness VIS:0 VAL:0\r\n");

    analogWrite(led::PIN, 0);
  }
  else if (msg.startsWith("@brightness")) {
    const int idx = msg.indexOf(' ');

    if (idx > 0) {
      const int val = msg.substring(idx + 1).toInt();

      if (val >= 0 && val <= 100) {
        Serial.print("GUI-O app is requesting LIGHT BRIGHTNESS: ");
        Serial.println(val);

        const int pwmValue = map(val, 0, 100, 0, 255);
        analogWrite(led::PIN, pwmValue);
      }
    }
  }
}

I just used Chat to port the code from ESP32 on the GUI-O website. Should work...

Best regards,
Kl3m3n